Apparatus for shaping pavement

ABSTRACT

An apparatus for shaping pavement, the apparatus comprising: a pavement-shaping member for receiving a flow of shapeless pavement material and generating a flow of shaped pavement material; and a paving machine mount, operably coupled to the pavement-shaping member, for coupling the pavement-shaping member to a paving machine, the pavement-shaping member comprising a concave pavement-shaping surface being disposed at a pavement ramp angle less than about 45 degrees and having a single radius of curvature less than about 60 inches.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of provisional application 61225489, filed Jul. 14, 2009.

BACKGROUND

The present invention relates generally to the field of roadway paving equipment and more specifically to the field of pavement-shaping devices.

As used herein: “pavement” refers to any material—including, without limitation, asphalt concrete, Portland cement concrete, soil, or gravel—laid down over a pre-existing roadway; “roadway” refers to any surface on which a paving machine (paver) may be driven including, without limitation, streets, roads, highways, driveways, bicycle paths, jogging paths, and runways; “paving” refers to the process of laying down pavement.

In a wide variety of applications, pavement-shaping devices are used to produce a desired shape at the edge of a paved roadway. Often, the desired shape provides a ramp to allow vehicles to more easily and more safely regain the roadway after inadvertently driving off the edge.

Typically, a conventional pavement-shaping device uses a planar pavement-shaping surface to produce a planar ramp. It is believed, however, that a convex ramp, produced by a concave pavement-shaping surface, has several advantages over the planar ramp including, without limitation, larger load capacity, longer life, and a smoother, more comfortably driven transition from ramp to paved roadway.

Typically, a conventional pavement-shaping device mounted to a paver's screed extension, is free to move in a plane parallel to the screed extension. Such motion often allows pavement to become trapped between the conventional pavement-shaping device and the paver's endgate and necessitates a work stoppage for repair. Preventing such motion keeps the gap between the pavement-shaping device and the endgate small enough to prevent pavement from being trapped and thus improves paver mission reliability.

Typically, a conventional pavement-shaping device is asymmetrical, necessitating different designs for mounting on the left and right sides of the paving machine and requiring both designs be purchased if paving in both directions is desired. By enforcing the proper symmetry, however, a single symmetrical design can be assembled for mounting on either the right side or left side of the paving machine.

Opportunities exist, therefore, to provide an improved pavement-shaping device with one or more of the following features: produces a convex ramp, prevents motion in the plane parallel to the screed extension, allows mounting on either the right side or left side of the paving machine.

SUMMARY

The opportunities described above are addressed, in one embodiment of the present invention, by an apparatus for shaping pavement, the apparatus comprising: a pavement-shaping member for receiving a flow of shapeless pavement material and generating a flow of shaped pavement material; and a paving machine mount, operably coupled to the pavement-shaping member, for coupling the pavement-shaping member to a paving machine, the pavement-shaping member comprising a concave pavement-shaping surface being disposed at a pavement ramp angle less than about 45 degrees and having a single radius of curvature less than about 60 inches.

DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 illustrates an isometric drawing in accordance with one embodiment of the present invention.

FIG. 2 illustrates an isometric drawing in accordance with an alternative embodiment of the present invention.

DETAILED DESCRIPTION

In accordance with one embodiment of the present invention, FIG. 1 illustrates an isometric drawing of an apparatus 100 for shaping pavement. Apparatus 100 comprises a pavement-shaping member 110 and a paving machine mount 115. In operation, paving machine 130 proceeds in the direction of travel shown. The direction of travel is thus also the “forward” direction. To an observer sitting on apparatus 100, therefore, a flow of shapeless pavement material appears to flow in the opposite direction. Pavement-shaping member 110 receives this flow of shapeless pavement material and generates a flow of shaped pavement material. Paving machine mount 115 is operably coupled to pavement-shaping member 110 and couples pavement-shaping member 110 to paving machine 130. Pavement-shaping member 110 comprises a concave pavement-shaping surface 150. Pavement-shaping surface 150 is disposed at a pavement ramp angle less than about 45 degrees and has a single radius of curvature less than about 60 inches. Having a single radius of curvature makes pavement-shaping surface 150 a portion of a right circular cylinder with a circular arc for cross section. The pavement ramp angle is the angle between the longest chord of that circular arc and the plane of the pre-existing roadway.

In a more detailed embodiment in accordance with the embodiment of FIG. 1, paving machine mount 115 is mechanically coupled to an endgate 200 of paving machine 130.

In another more detailed embodiment in accordance with the embodiment of FIG. 1, the pavement ramp angle is about 30 degrees.

In another more detailed embodiment in accordance with the embodiment of FIG. 1, the single radius of curvature is about 48 inches.

In another more detailed embodiment in accordance with the embodiment of FIG. 1, paving machine mount 115 is symmetric top-to-bottom and pavement-shaping member 110 is symmetric front-to-back. These symmetries allow apparatus 100 to be assembled on either the right side (as shown in FIG. 1) or the left side of paving machine 130.

In accordance with an alternative embodiment of the present invention, FIG. 2 illustrates an isometric drawing wherein apparatus 100 further comprises a pair of vertical restraining surfaces 120. In operation, vertical restraining surfaces 120 mechanically couple to paving machine mount 115 and prevent motion of pavement-shaping member 110 in a plane parallel to screed extension 210 of paving machine 130. Pavement-shaping member 110 is slidably coupled to vertical restraining surfaces 120 and paving machine mount 115 is mechanically coupled to screed extension 210.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, apparatus 100 further comprises a vertical guide rail 160. In operation, vertical guide rail 160 lifts pavement-shaping member 110 to follow off-road terrain. Vertical guide rail 160 is removably coupled to, and extends forward of, pavement-shaping member 110. To facilitate sliding over rough terrain, vertical guide rail 160 has a corner radius greater than about 0.2 inches.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, the corner radius is about 2 inches.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, vertical guide rail 160 is symmetric top-to-bottom and pavement-shaping member 110 is symmetric front-to-back. These symmetries allow apparatus 100 to be assembled on either the right side (as shown in FIG. 1) or the left side of paving machine 130.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, apparatus 100 further comprises a compression spring 170 disposed for transmitting a downward force from paving machine mount 115 to pavement-shaping member 110. Compression spring 170 is any mechanical component capable of be compressed and of transmitting a downward force. Common examples of compression springs include, without limitation, gas springs, straight coils, hourglass coils, conical coils, barrel coils, die springs, ground end springs, and closed- or square-end coils.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, compression spring 170 has a spring rate of about 100 pounds per inch.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, compression spring 170 is a die spring.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, apparatus 100 further comprises a load cell 180 disposed and coupled for measuring downward force. Load cell 180 refers to a force sensor. In some embodiments, the output of load cell 180 is displayed to the paving machine operator for quality control purposes. For sensing force, load cell 180 may use, for example, capacitive, resistive, optical, or piezoelectric sensing means.

In a more detailed embodiment in accordance with the embodiment of FIG. 2, apparatus 100 further comprises a vibrator 190 disposed and coupled for applying a vibration force to pavement-shaping member 110. This vibration force is thought to aid in the compaction of the convex ramp formed. Vibrator 190 refers to any device, assembly, or combination thereof capable of creating a vibration. Vibrator 190 may be embodied, without limitation, as a piezoelectric cell, micro-electromechanical systems (MEMS) device, or any electromechanical, mechanical, acoustical, optical, or chemical vibration source.

While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. 

1. An apparatus for shaping pavement, said apparatus comprising: a pavement-shaping member for receiving a flow of shapeless pavement material and generating a flow of shaped pavement material; and a paving machine mount, operably coupled to said pavement-shaping member, for coupling said pavement-shaping member to a paving machine, said pavement-shaping member comprising a concave pavement-shaping surface being disposed at a pavement ramp angle less than about 45 degrees and having a single radius of curvature less than about 60 inches.
 2. The apparatus of claim 1 wherein said paving machine mount is mechanically coupled to an endgate of said paving machine.
 3. The apparatus of claim 1 wherein said pavement ramp angle is about 30 degrees.
 4. The apparatus of claim 1 wherein said single radius of curvature is about 48 inches.
 5. The apparatus of claim 1 wherein said paving machine mount is symmetric top-to-bottom and said pavement-shaping member is symmetric front-to-back.
 6. The apparatus of claim 1 further comprising a pair of vertical restraining surfaces, mechanically coupled to said paving machine mount, for preventing motion of said pavement-shaping member in a plane parallel to a screed extension of said paving machine, said pavement-shaping member being slidably coupled to said vertical restraining surfaces, said paving machine mount being mechanically coupled to said screed extension.
 7. The apparatus of claim 6 further comprising a vertical guide rail for lifting said pavement-shaping member and following off-road terrain, said vertical guide rail being removably coupled to and extending forward of said pavement-shaping member and having a corner radius greater than about 0.2 inches.
 8. The apparatus of claim 7 wherein said corner radius is about 2 inches.
 9. The apparatus of claim 7 wherein said vertical guide rail is symmetric top-to-bottom and said pavement-shaping member is symmetric front-to-back.
 10. The apparatus of claim 6 further comprising a compression spring disposed for transmitting a downward force from said paving machine mount to said pavement-shaping member.
 11. The apparatus of claim 10 wherein said compression spring has a spring rate of about 100 pounds per inch.
 12. The apparatus of claim 10 wherein said compression spring is a die spring.
 13. The apparatus of claim 10 further comprising a load cell disposed and coupled for measuring said downward force.
 14. The apparatus of claim 6 further comprising a vibrator disposed and coupled for applying a vibration force to pavement-shaping member.
 15. An apparatus for shaping pavement, said apparatus comprising: a pavement-shaping member for receiving a flow of shapeless pavement material and generating a flow of shaped pavement material; and a paving machine mount, operably coupled to said pavement-shaping member, for coupling said pavement-shaping member to a paving machine, a pair of vertical restraining surfaces, mechanically coupled to said paving machine mount, for preventing motion of said pavement-shaping member in a plane parallel to a screed extension of said paving machine, said pavement-shaping member being slidably coupled to said vertical restraining surfaces, said paving machine mount being mechanically coupled to said screed extension, said pavement-shaping member comprising a concave pavement-shaping surface being disposed at a pavement ramp angle of about 30 degrees and having a single radius of curvature of about 48 inches.
 16. The apparatus of claim 15 further comprising a vertical guide rail for lifting said pavement-shaping member and following off-road terrain, said vertical guide rail being removably coupled to and extending forward of said pavement-shaping member and having a corner radius greater than about 0.2 inches.
 17. The apparatus of claim 16 wherein said corner radius is about 2 inches.
 18. The apparatus of claim 16 wherein said vertical guide rail is symmetric top-to-bottom and said pavement-shaping member is symmetric front-to-back.
 19. The apparatus of claim 15 further comprising a compression spring disposed for transmitting a downward force from said paving machine mount to said pavement-shaping member.
 20. The apparatus of claim 19 wherein said compression spring has a spring rate of about 100 pounds per inch.
 21. The apparatus of claim 19 wherein said compression spring is a die spring.
 22. The apparatus of claim 19 further comprising a load cell disposed and coupled for measuring said downward force.
 23. The apparatus of claim 15 further comprising a vibrator disposed and coupled for applying a vibration force to said pavement-shaping member. 